Anxiolytic effects of Julibroside C1 isolated from Albizzia julibrissin in mice

Julibroside C-1 is a saponin-containing compound isolated from Albizzia julibrissin Durazz. In this study, we investigated the putative anxiolytic effects ofJulibroside C-1 using the elevated plus maze (EPM) in mice. Julibroside C-1 at doses of 0.5 and 1 mg/kg significantly increased the time spent in the open arms and the number of entries into the open arms of the EPM compared to the control group. Moreover, the anxiolytic-like effects of Julibroside (0.5 mg/kg) were blocked by WAY-100635 (5-HT1A receptor antagonist), bicuculline (GABA(A) receptor antagonist), and flumazenil (antagonist of the GABAA receptor benzodiazepine site). However, Julibroside C-1 did not change locomotor activity or induce myorelaxant effects. We used quantitative receptor autoradiography to investigate the effects of Julibroside C-1 on alterations in mouse brain receptors. After acute treatment with Julibroside (0.5 mg/kg), [H-3]-8-0H-DPAT binding was significantly decreased in the CA1 region of the hippocampus and [H-3]-flunitrazepam binding was decreased remarkably in the cingulate cortex region. However, [H-3]-muscimol binding did not show a significant change in any brain region. Taken together, our findings suggest that Julibroside C1 shows anxiolytic-like effects, which might be mediated by the 5-HT1A and GABA(A)-benzodiazepine receptor systems. (C) 2013 Elsevier Inc. All rights reserved.